Abstract
We functionally characterized the grape (Vitis vinifera) VvPIP2;4N (for Plasma membrane Intrinsic Protein) aquaporin gene. Expression of VvPIP2;4N in Xenopus laevis oocytes increased their swelling rate 54-fold. Northern blot and quantitative reverse transcription-polymerase chain reaction analyses showed that VvPIP2;4N is the most expressed PIP2 gene in root. In situ hybridization confirmed root localization in the cortical parenchyma and close to the endodermis. We then constitutively overexpressed VvPIP2;4N in grape 'Brachetto', and in the resulting transgenic plants we analyzed (1) the expression of endogenous and transgenic VvPIP2;4N and of four other aquaporins, (2) whole-plant, root, and leaf ecophysiological parameters, and (3) leaf abscisic acid content. Expression of transgenic VvPIP2;4N inhibited neither the expression of the endogenous gene nor that of other PIP aquaporins in both root and leaf. Under well-watered conditions, transgenic plants showed higher stomatal conductance, gas exchange, and shoot growth. The expression level of VvPIP2;4N (endogenous + transgene) was inversely correlated to root hydraulic resistance. The leaf component of total plant hydraulic resistance was low and unaffected by overexpression of VvPIP2;4N. Upon water stress, the overexpression of VvPIP2;4N induced a surge in leaf abscisic acid content and a decrease in stomatal conductance and leaf gas exchange. Our results show that aquaporin-mediated modifications of root hydraulics play a substantial role in the regulation of water flow in well-watered grapevine plants, while they have a minor role upon drought, probably because other signals, such as abscisic acid, take over the control of water flow.
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Claims 10
Claim · model-written summary
VvPIP2;4N expression increased oocyte swelling 54-fold.
VitisOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Expression of VvPIP2;4N in Xenopus laevis oocytes increased their swelling rate 54-fold.”
t0“Grapevine”
Claim · model-written summary
VvPIP2;4N was the most expressed root PIP2 gene.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“VvPIP2;4N is the most expressed PIP2 gene in root.”
t0“Grapevine”
Claim · model-written summary
VvPIP2;4N localized in cortical parenchyma near the endodermis.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“root localization in the cortical parenchyma and close to the endodermis.”
e1“We functionally characterized the grape (Vitis vinifera) VvPIP2;4N”
t0“Grapevine”
Claim · model-written summary
Transgene expression did not inhibit endogenous or other PIP aquaporin expression in roots and leaves.
- Treatment
- transgenic VvPIP2;4Ne0
- Outcome
- expression of the endogenous gene nor that of other PIP aquaporinse0
- Direction
- inhibited neithere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Expression of transgenic VvPIP2;4N inhibited neither the expression of the endogenous gene nor that of other PIP aquaporins in both root and leaf.”
t0“Grapevine”
Claim · model-written summary
Well-watered transgenic grape had higher stomatal conductance and gas exchange.
- Treatment
- transgenic plantse0
- Outcome
- stomatal conductance, gas exchangee0
- Direction
- highere0
- Qualifier
- well-watered conditionse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under well-watered conditions, transgenic plants showed higher stomatal conductance, gas exchange, and shoot growth.”
t0“Grapevine”
Claim · model-written summary
Well-watered transgenic grape had higher shoot growth.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under well-watered conditions, transgenic plants showed higher stomatal conductance, gas exchange, and shoot growth.”
t0“Grapevine”
Claim · model-written summary
VvPIP2;4N expression was inversely correlated with root hydraulic resistance.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The expression level of VvPIP2;4N (endogenous + transgene) was inversely correlated to root hydraulic resistance.”
t0“Grapevine”
Claim · model-written summary
Leaf hydraulic resistance was low and unaffected by VvPIP2;4N overexpression.
- Treatment
- overexpression of VvPIP2;4Ne0
- Outcome
- leaf component of total plant hydraulic resistancee0
- Direction
- unaffectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The leaf component of total plant hydraulic resistance was low and unaffected by overexpression of VvPIP2;4N.”
t0“Grapevine”
Claim · model-written summary
Under water stress, overexpression raised leaf abscisic acid content.
- Treatment
- overexpression of VvPIP2;4Ne0
- Outcome
- leaf abscisic acid contente0
- Direction
- surgee0
- Qualifier
- water stresse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Upon water stress, the overexpression of VvPIP2;4N induced a surge in leaf abscisic acid content and a decrease in stomatal conductance and leaf gas exchange.”
t0“Grapevine”
Claim · model-written summary
Under water stress, overexpression decreased stomatal conductance and leaf gas exchange.
- Treatment
- overexpression of VvPIP2;4Ne0
- Outcome
- stomatal conductance and leaf gas exchangee0
- Direction
- decreasee0
- Qualifier
- water stresse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Upon water stress, the overexpression of VvPIP2;4N induced a surge in leaf abscisic acid content and a decrease in stomatal conductance and leaf gas exchange.”
t0“Grapevine”
The same questions in other papers
transgenic · molecular: expression · VitisPositive and negative results
2 in the opposite direction
- positive
- positive
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.